diff --git a/src/internal/poll/fd_windows.go b/src/internal/poll/fd_windows.go
index edad6563508bc6..7953ad6aac9f90 100644
--- a/src/internal/poll/fd_windows.go
+++ b/src/internal/poll/fd_windows.go
@@ -149,7 +149,7 @@ var wsaMsgPool = sync.Pool{
 
 // newWSAMsg creates a new WSAMsg with the provided parameters.
 // Use [freeWSAMsg] to free it.
-func newWSAMsg(p []byte, oob []byte, flags int, unconnected bool) *windows.WSAMsg {
+func newWSAMsg(p []byte, oob []byte, flags int, rsa *wsaRsa) *windows.WSAMsg {
 	// The returned object can't be allocated in the stack because it is accessed asynchronously
 	// by Windows in between several system calls. If the stack frame is moved while that happens,
 	// then Windows may access invalid memory.
@@ -164,34 +164,46 @@ func newWSAMsg(p []byte, oob []byte, flags int, unconnected bool) *windows.WSAMs
 		Buf: unsafe.SliceData(oob),
 	}
 	msg.Flags = uint32(flags)
-	if unconnected {
-		msg.Name = wsaRsaPool.Get().(*syscall.RawSockaddrAny)
-		msg.Namelen = int32(unsafe.Sizeof(syscall.RawSockaddrAny{}))
+	if rsa != nil {
+		msg.Name = &rsa.name
+		msg.Namelen = rsa.namelen
 	}
 	return msg
 }
 
 func freeWSAMsg(msg *windows.WSAMsg) {
 	// Clear pointers to buffers so they can be released by garbage collector.
+	msg.Name = nil
+	msg.Namelen = 0
 	msg.Buffers.Len = 0
 	msg.Buffers.Buf = nil
 	msg.Control.Len = 0
 	msg.Control.Buf = nil
-	if msg.Name != nil {
-		*msg.Name = syscall.RawSockaddrAny{}
-		wsaRsaPool.Put(msg.Name)
-		msg.Name = nil
-		msg.Namelen = 0
-	}
 	wsaMsgPool.Put(msg)
 }
 
+// wsaRsa bundles a [syscall.RawSockaddrAny] with its length for efficient caching.
+//
+// When used by WSARecvFrom, wsaRsa must be on the heap. See
+// https://learn.microsoft.com/en-us/windows/win32/api/winsock2/nf-winsock2-wsarecvfrom.
+type wsaRsa struct {
+	name    syscall.RawSockaddrAny
+	namelen int32
+}
+
 var wsaRsaPool = sync.Pool{
 	New: func() any {
-		return new(syscall.RawSockaddrAny)
+		return new(wsaRsa)
 	},
 }
 
+func newWSARsa() *wsaRsa {
+	rsa := wsaRsaPool.Get().(*wsaRsa)
+	rsa.name = syscall.RawSockaddrAny{}
+	rsa.namelen = int32(unsafe.Sizeof(syscall.RawSockaddrAny{}))
+	return rsa
+}
+
 var operationPool = sync.Pool{
 	New: func() any {
 		return new(operation)
@@ -737,19 +749,18 @@ func (fd *FD) ReadFrom(buf []byte) (int, syscall.Sockaddr, error) {
 
 	fd.pin('r', &buf[0])
 
-	rsa := wsaRsaPool.Get().(*syscall.RawSockaddrAny)
+	rsa := newWSARsa()
 	defer wsaRsaPool.Put(rsa)
 	n, err := fd.execIO('r', func(o *operation) (qty uint32, err error) {
-		rsan := int32(unsafe.Sizeof(*rsa))
 		var flags uint32
-		err = syscall.WSARecvFrom(fd.Sysfd, newWsaBuf(buf), 1, &qty, &flags, rsa, &rsan, &o.o, nil)
+		err = syscall.WSARecvFrom(fd.Sysfd, newWsaBuf(buf), 1, &qty, &flags, &rsa.name, &rsa.namelen, &o.o, nil)
 		return qty, err
 	})
 	err = fd.eofError(n, err)
 	if err != nil {
 		return n, nil, err
 	}
-	sa, _ := rsa.Sockaddr()
+	sa, _ := rsa.name.Sockaddr()
 	return n, sa, nil
 }
 
@@ -768,19 +779,18 @@ func (fd *FD) ReadFromInet4(buf []byte, sa4 *syscall.SockaddrInet4) (int, error)
 
 	fd.pin('r', &buf[0])
 
-	rsa := wsaRsaPool.Get().(*syscall.RawSockaddrAny)
+	rsa := newWSARsa()
 	defer wsaRsaPool.Put(rsa)
 	n, err := fd.execIO('r', func(o *operation) (qty uint32, err error) {
-		rsan := int32(unsafe.Sizeof(*rsa))
 		var flags uint32
-		err = syscall.WSARecvFrom(fd.Sysfd, newWsaBuf(buf), 1, &qty, &flags, rsa, &rsan, &o.o, nil)
+		err = syscall.WSARecvFrom(fd.Sysfd, newWsaBuf(buf), 1, &qty, &flags, &rsa.name, &rsa.namelen, &o.o, nil)
 		return qty, err
 	})
 	err = fd.eofError(n, err)
 	if err != nil {
 		return n, err
 	}
-	rawToSockaddrInet4(rsa, sa4)
+	rawToSockaddrInet4(&rsa.name, sa4)
 	return n, err
 }
 
@@ -799,19 +809,18 @@ func (fd *FD) ReadFromInet6(buf []byte, sa6 *syscall.SockaddrInet6) (int, error)
 
 	fd.pin('r', &buf[0])
 
-	rsa := wsaRsaPool.Get().(*syscall.RawSockaddrAny)
+	rsa := newWSARsa()
 	defer wsaRsaPool.Put(rsa)
 	n, err := fd.execIO('r', func(o *operation) (qty uint32, err error) {
-		rsan := int32(unsafe.Sizeof(*rsa))
 		var flags uint32
-		err = syscall.WSARecvFrom(fd.Sysfd, newWsaBuf(buf), 1, &qty, &flags, rsa, &rsan, &o.o, nil)
+		err = syscall.WSARecvFrom(fd.Sysfd, newWsaBuf(buf), 1, &qty, &flags, &rsa.name, &rsa.namelen, &o.o, nil)
 		return qty, err
 	})
 	err = fd.eofError(n, err)
 	if err != nil {
 		return n, err
 	}
-	rawToSockaddrInet6(rsa, sa6)
+	rawToSockaddrInet6(&rsa.name, sa6)
 	return n, err
 }
 
@@ -1371,7 +1380,9 @@ func (fd *FD) ReadMsg(p []byte, oob []byte, flags int) (int, int, int, syscall.S
 		p = p[:maxRW]
 	}
 
-	msg := newWSAMsg(p, oob, flags, true)
+	rsa := newWSARsa()
+	defer wsaRsaPool.Put(rsa)
+	msg := newWSAMsg(p, oob, flags, rsa)
 	defer freeWSAMsg(msg)
 	n, err := fd.execIO('r', func(o *operation) (qty uint32, err error) {
 		err = windows.WSARecvMsg(fd.Sysfd, msg, &qty, &o.o, nil)
@@ -1396,7 +1407,9 @@ func (fd *FD) ReadMsgInet4(p []byte, oob []byte, flags int, sa4 *syscall.Sockadd
 		p = p[:maxRW]
 	}
 
-	msg := newWSAMsg(p, oob, flags, true)
+	rsa := newWSARsa()
+	defer wsaRsaPool.Put(rsa)
+	msg := newWSAMsg(p, oob, flags, rsa)
 	defer freeWSAMsg(msg)
 	n, err := fd.execIO('r', func(o *operation) (qty uint32, err error) {
 		err = windows.WSARecvMsg(fd.Sysfd, msg, &qty, &o.o, nil)
@@ -1420,7 +1433,9 @@ func (fd *FD) ReadMsgInet6(p []byte, oob []byte, flags int, sa6 *syscall.Sockadd
 		p = p[:maxRW]
 	}
 
-	msg := newWSAMsg(p, oob, flags, true)
+	rsa := newWSARsa()
+	defer wsaRsaPool.Put(rsa)
+	msg := newWSAMsg(p, oob, flags, rsa)
 	defer freeWSAMsg(msg)
 	n, err := fd.execIO('r', func(o *operation) (qty uint32, err error) {
 		err = windows.WSARecvMsg(fd.Sysfd, msg, &qty, &o.o, nil)
@@ -1444,15 +1459,18 @@ func (fd *FD) WriteMsg(p []byte, oob []byte, sa syscall.Sockaddr) (int, int, err
 	}
 	defer fd.writeUnlock()
 
-	msg := newWSAMsg(p, oob, 0, sa != nil)
-	defer freeWSAMsg(msg)
+	var rsa *wsaRsa
 	if sa != nil {
+		rsa = newWSARsa()
+		defer wsaRsaPool.Put(rsa)
 		var err error
-		msg.Namelen, err = sockaddrToRaw(msg.Name, sa)
+		rsa.namelen, err = sockaddrToRaw(&rsa.name, sa)
 		if err != nil {
 			return 0, 0, err
 		}
 	}
+	msg := newWSAMsg(p, oob, 0, rsa)
+	defer freeWSAMsg(msg)
 	n, err := fd.execIO('w', func(o *operation) (qty uint32, err error) {
 		err = windows.WSASendMsg(fd.Sysfd, msg, 0, nil, &o.o, nil)
 		return qty, err
@@ -1471,11 +1489,14 @@ func (fd *FD) WriteMsgInet4(p []byte, oob []byte, sa *syscall.SockaddrInet4) (in
 	}
 	defer fd.writeUnlock()
 
-	msg := newWSAMsg(p, oob, 0, sa != nil)
-	defer freeWSAMsg(msg)
+	var rsa *wsaRsa
 	if sa != nil {
-		msg.Namelen = sockaddrInet4ToRaw(msg.Name, sa)
+		rsa = newWSARsa()
+		defer wsaRsaPool.Put(rsa)
+		rsa.namelen = sockaddrInet4ToRaw(&rsa.name, sa)
 	}
+	msg := newWSAMsg(p, oob, 0, rsa)
+	defer freeWSAMsg(msg)
 	n, err := fd.execIO('w', func(o *operation) (qty uint32, err error) {
 		err = windows.WSASendMsg(fd.Sysfd, msg, 0, nil, &o.o, nil)
 		return qty, err
@@ -1494,11 +1515,14 @@ func (fd *FD) WriteMsgInet6(p []byte, oob []byte, sa *syscall.SockaddrInet6) (in
 	}
 	defer fd.writeUnlock()
 
-	msg := newWSAMsg(p, oob, 0, sa != nil)
-	defer freeWSAMsg(msg)
+	var rsa *wsaRsa
 	if sa != nil {
-		msg.Namelen = sockaddrInet6ToRaw(msg.Name, sa)
+		rsa = newWSARsa()
+		defer wsaRsaPool.Put(rsa)
+		rsa.namelen = sockaddrInet6ToRaw(&rsa.name, sa)
 	}
+	msg := newWSAMsg(p, oob, 0, rsa)
+	defer freeWSAMsg(msg)
 	n, err := fd.execIO('w', func(o *operation) (qty uint32, err error) {
 		err = windows.WSASendMsg(fd.Sysfd, msg, 0, nil, &o.o, nil)
 		return qty, err